title: Mechanism governing reversal of multidrug resistance in human breast carcinoma cells by chelerythrine.
abstract: OBJECTIVE
  To explore the mechanism governing the reversal of multidrug resistance in human breast carcinoma cells by chelerythrine.
  
  
  METHODS
  Reverse transcription-polymerase chain reaction (RT-PCR) and Western blot were used to determine the expressions of protein kinase Cα (PKCα) and multidrug resistance-related genes ABCG2, ABCC1, MDR1, and P-glycoprotein (P-gp) in MCF-7Taxol cells after treatment with chelerythrine and phorbol-12-myristate-13-acetate (PMA). Also, the antitumor effect of PMA or chelerythrine and effects of PKCα activator or inhibitor in combination with paclitaxel or adriamycin on multidrug resistance in MCF-7Taxol cells were evaluated by MTT.
  
  
  RESULTS
  RT-PCR or Western blot showed that the expressions of MDR1 and P-gp were significantly higher in MCF-7Taxol cells exposed to PMA stimuli (both P0.05).
  
  
  CONCLUSIONS
  PKCα inhibitor chelerythrine can reverse multidrug resistance in breast carcinoma cells by inhibiting the expressions of MDR1 and P-gp expression in vitro.
authors.affiliation: Laboratory Center for Basic Medical Sciences, Nanjing Medical University, Nanjing 210029, China.
authors.forename: Cao
authors.initials: C
authors.lastname: Zhe
authors.forename: Wang
authors.initials: W
authors.lastname: Li-Juan
authors.forename: Wu
authors.initials: W
authors.lastname: Ming Hui
authors.forename: Jiao
authors.initials: J
authors.lastname: Yu
authors.forename: Sun
authors.initials: S
authors.lastname: Yu Jie
authors.forename: Guo
authors.initials: G
authors.lastname: Jun
mesh_terms: D018435:ATP Binding Cassette Transporter, Subfamily B; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000378:metabolism; D053119:Benzophenanthridines / Q000494:pharmacology*; D001943:Breast Neoplasms / Q000378:metabolism / Q000473:pathology; D045744:Cell Line, Tumor; D018432:Drug Resistance, Multiple / Q000187:drug effects*; D019008:Drug Resistance, Neoplasm / Q000187:drug effects*; D005260:Female; D006801:Humans
chemical_list: C513055:ABCB1 protein, human; D018435:ATP Binding Cassette Transporter, Subfamily B; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D053119:Benzophenanthridines; C016299:chelerythrine